package ThreadDemo;

// 此处不考虑泛型参数, 只是基于 String 进行存储.
class myBlockingQueue {
    private String[] data = null;
    private volatile int head = 0;
    private volatile int tail = 0;
    private volatile int size = 0;

    private Object locker = new Object();

    public myBlockingQueue(int capacity) {
        data = new String[capacity];
    }

    public void put(String s) throws InterruptedException {
        // 加锁的对象, 可以单独定义一个, 也可以直接就地使用 this.
        synchronized (this) {
            while (size == data.length) {
                // 队列满了
                // return;
                this.wait();
            }
            data[tail] = s;
            tail++;
            if (tail >= data.length) {
                tail = 0;
            }
            size++;

            this.notify();
        }
    }

    public String take() throws InterruptedException{
        String ret = "";
        synchronized (this) {
            while (size == 0) {
                // 队列为空
                // return null;
                this.wait();
            }
            ret = data[head];
            head++;
            if (head >= data.length) {
                head = 0;
            }
            size--;

            this.notify();
        }
        return ret;
    }
}//test01

